For example, as the electric wire used for a wire harness that is mounted to a vehicle, the shielded electric wire that prevents influences of external noises such as an electromagnetic wave, etc. and prevents such an event that radiant noises such as an electromagnetic wave, etc. leak out to an outside from the electric wire is employed. According to this shielded electric wire, a core wire is shielded with a shielding member such as a braided shield, or the like, and then this shielding member is ground-connected to either a member that is electrically connected to a common ground portion in the vehicle or a mounted body as the common ground portion itself.
Also, as an example of the ground connecting methods applied to this shielded electric wire, the following method is commonly known. That is, the ground connecting method is applied such that an outer cover of the shielded electric wire is peeled off to expose the braided shields as a shielding member, then the braided shields are twisted into one member, then a ground connecting terminal is fixed to one end of this member by the clamping process, then the exposed portion of the braided shields is sheathed with a heat shrinkable tube, an insulating tape, or the like and is subjected to an insulating process, as occasion demands, and then a ground connecting terminal is fixed to be connected electrically to the mounted body. However, according to such ground connecting method, a large number of complicated man-hours are required of the ground connection, and therefore workability becomes worse.
Meanwhile, the shielded electric wire connector used to connect the shielded electric wire is set forth in Patent Literature 1, for example. As shown in FIG. 5, this shielded electric wire connector 30 has a shielding pipe 32 fitted in a housing 34 to shield a connection portion of a shielded electric wire 31, and a shielding connection component 35 for connecting electrically a shielding layer 33 of the shielded electric wire 31 and the shielding pipe 32. In this shielded electric wire connector 30, the shielding connection component 35 consists of two half components 37. The half components 37 are formed such that these components, when coupled together, clamp the shielding layer 33 exposed on an insulating layer 36 of the shielded electric wire. Also, each of two half components 37 consists of a metal parts 38 and a resin parts 39, both of which are integrated into one piece.
The metal parts 38 has an inner peripheral side contact piece 41 on an inner peripheral portion of a semi-annular wall portion 37a. This inner peripheral side contact piece 41 is pressed against the shielding layer 33 or a metal tape 40 being wound on an outer periphery of this shielding layer 33. This semi-annular wall portion 37a blocks an annular clearance between the shielding layer 33 of the shielded electric wire 31 and the shielding pipe 32 over its about semicircle. Also, the metal parts 38 has integrally an outer peripheral side contact piece 42 on an outer peripheral portion of the semi-annular wall portion 37a. This outer peripheral side contact piece 42 contacts an inner peripheral surface of the shielding pipe 32. Each of the resin parts 39 has a coupling portion that is used to couple two half components 37 together. Also, the resin parts 39 are constructed to have a part P and a part Q respectively. These parts P clamp the shielding layer 33 of the shielded electric wire 31 via the inner peripheral side contact piece 41 of the metal parts 38. Also, these parts Q clamp directly a sheath 43 by causing their protruded brims 44 to cut into an outer peripheral surface of the sheath 43 of the shielded electric wire 31.
The shielding layer 33 is exposed at the top end portion of the sheath 43 of the shielded electric wire 31. The shielding layer 33 that contains a center conductor 45 at its center portion is exposed at the top end portion of this shielding layer 33. A female terminal 47 is connected to one end portion of the center conductor 45. In this shielded electric wire connector 30, when two half components 37 are coupled together so as to put the shielding layer 33 and the sheath 43 therebetween, the inner peripheral side contact pieces 41 of the metal parts 38 are pressed strongly against the metal tape 40 on the shielding layer 33.
Also, the protruded brims 44 formed at the rear end of the resin parts 39 are cut into the inner side from the surface of the sheath 43, so that integration of the shielding connection component 35 and the shielded electric wire 31 can be ensured. Also, the outer peripheral side contact piece 42 of the metal parts 38 is elastically deformed in the direction to reduce its diameter, and then the metal parts 38 comes into contact the inner peripheral surface of the shielding pipe 32 by an elastic repulsive force of the outer peripheral side contact piece 42. Accordingly, the shielding layer 33 and the shielding pipe 32 are brought into their electrically connected state. In other words, the shielding layer 33 is electrically connected to the shielded terminal of the opposing connector (not shown) and the mounted body such as the body of the car, the common ground portion, or the like via the shielding pipe 32.
However, in such shielded electric wire connector, the metal parts 38 and the resin parts 39 are interposed between the shielding layer 33 of the shielded electric wire 31 and the shielding pipe 32 to connect electrically them. Therefore, in order to make sure of this interposition, the shielding layer 33 and the sheath 43 must be press-fitted strongly by the inner peripheral side contact pieces 41 of the metal parts 38, which are formed as the press-fitted parts, and the protruded brims 44 of the resin parts 39 respectively. In this case, when a press-fitting force applied by the inner peripheral side contact pieces 41 and the protruded brims 44 is too strong, corner portions (edge portions) at which the inner peripheral side contact piece 41 and the semi-annular wall portion 37a are connected respectively are engaged in the insulating layer 36 serving as the inner cover via the shielding layer 33. As a result, it may be considered that a part (sharp edge portion) of the shielding layer 33 sticks into the insulating layer 36 to damage this insulating layer, or the like and thus a fault such as a short-circuit accident between the core wire and the shielding layer 33, or the like is caused. Also, such a fault is caused such that this sheath 43 is damaged due to the engagement of the protruded brims 44 into the sheath 43.
In the meantime, in order to avoid such damage of the insulating layer 36 or the sheath 43 caused by the press-fitting force, such a ground connecting structure has been proposed that the shielding sleeve should be interposed between the outer cover (sheath) of the shielded electric wire and the braided shield that is folded back on the outer peripheral surface of the cut end portion of this outer cover (see Patent Literature 2, for example). FIG. 6 is a longitudinal sectional view showing a ground connector having such ground connecting structure.
A ground connector 61 is used to electrically connect (i.e., ground-connect) a braided shield (shielding member) 63 of a shielded electric wire 64 to the mounted body. This shielded electric wire 64 contains a core wire 62 and the braided shield 63 that is extended along the longitudinal direction of the core wire 62 to sheathe the core wire 62. Concretely, the ground connector 61 contains a conductive shielding terminal 65 being fitted to the shielded electric wire 64 such that this terminal 65 is connected electrically to the braided shield 63, and a conductive ground member 66 being fixed such that this member 66 is connected electrically to the mounted body which the shielding terminal 65 contacts and to which the shielding terminal 65 is electrically connected.
The ground member 66 is formed by bending a plate-like conductive member whose thickness is 2 mm, for example, like an almost L shape. Also, a through hole 66d (e.g., diameter of 14 mm) that is connected electrically to the shielding terminal 65 is formed in the ground member 66. The through hole 66d may be formed as a simple circular hole that has the identical diameter (e.g., diameter of 14 mm) to an outer diameter of a small diameter part 66b of a shielding contact 67 that constitutes a part of the shielding terminal 65. Alternately, the through hole 66d may be formed in the form that a concave recess (not shown), which enables the shielded electric wire 64 with the press-fitted terminal to be easily inserted into the through hole 66d even in a state that the press-fitted terminal (the connection terminal) is already fitted to the end portion (in FIG. 6, the right end portion) of the core wire 62 of the shielded electric wire 64 by the press-fitting, should be contained.
Then, the shielded electric wire 64 with the press-fitted terminal is passed through the through hole 66d of the ground member 66, and thus the shielding terminal 65 can be connected to the contact portion of the ground member 66. A part of the ground member 66, which is bent like an L shape, constitutes the connection portion that is connected electrically and fixed to the mounted body. This mounted body corresponds to the member that is connected electrically to the common ground portion in the vehicle or the common ground portion itself, for example.
The shielding terminal 65 consists of the shielding contact 67 and a shielding sleeve 68. This shielding contact 67 is formed of a conductive member of a hollow annular (pipe) shape. The shielding contact 67 is formed by linking together a large diameter part 67a of a hollow annular shape and the small diameter part 66b of a hollow annular shape. An open end of the large diameter part 67a is expanded in diameter outwardly in the radial direction by the curling, and also an open end of the small diameter part 66b is reduced in diameter like a taper shape. Also, this shielding sleeve 68 is formed of a conductive member of a hollow annular (pipe) shape. Here, in the shielded electric wire 64 to which the ground connector 61 is fitted, the core wire 62 is covered with an inner cover 69 as the insulating member, the inner cover 69 is covered with the braided shield 63 as a netlike conductor (i.e., shielding member), and the braided shield 63 is covered with an outer cover 70 as the insulating member.
In this ground connector, such processes are applied to one end portion of the shielded electric wire 64 that one end portion of the outer cover 70 is peeled off in a predetermined length to expose one end portion of the braided shield 63, then the shielded electric wire 64 is passed through the shielding sleeve 68, then the shielding sleeve 68 is arranged around one end portion of the outer cover 70 located near one end portion of the exposed braided shield 63, and then one end portion of the exposed braided shield 63 is folded back like an almost U shape in section to cover the outer peripheral surface of the shielding sleeve 68. Then, the large diameter part 67a of the shielding contact 67 is fitted onto one end portion of the folded-back braided shield 63, and then the large diameter part 67a as well as the shielding sleeve 68 and the shielded electric wire 64 is reduced in diameter by the clamping. Thus, the shielding contact 67, the shielding sleeve 68, and the braided shield 63 can be brought into a mutual conduction state without fail.